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From: John Woodgate
Newsgroups: sci.electronics.design,sci.electronics.misc
Subject: Re: Sound cancellation technology?
Date: Thu, 26 Dec 2002 11:54:42 +0000
Organization: JMWA Electronics Consultancy
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References: <3e0a28fb$1_4@omega.dimensional.com>
Reply-To: John Woodgate
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I read in sci.electronics.design that Phil Allison
wrote (in ) about 'Sound
cancellation technology?', on Thu, 26 Dec 2002:
>
>"John Woodgate" wrote in message
>news:Kuf3NQAhIsC+EwTV@jmwa.demon.co.uk...
>> I read in sci.electronics.design that Lady Liberty
>> wrote (in > .124.0.13>) about 'Sound cancellation technology?', on Wed, 25 Dec 2002:
>> >Fine but not my question. Could someone please answer the actual
>question?
>> >
>> >
>> OK, it is almost certainly possible, but would be very costly, not
>> necessarily in terms of equipment but in the custom DSP software
>> required.
>
>
> ** Really ?
>
> How do you cancell by a factor of 60 dB *any* noise that intrudes
>into a bedroom ? This may include barking dogs next to the window, road
>traffic noise of all sorts at close range, aircraft noise, neighbours
>activity impacting the floor/ceiling interface with deep, powerfull sub
>sonics etc, etc.
>
> These create sudden and disturbing noise in the room at almost any
>frequency 60 dB or more above ambient with attendant internal reverberation
>and varying phase at any point and arriving from any of dozens of sources
>and directions ??
>
>
Well, your 60 dB appeared out of the woodwork, and such an extreme level
of cancellation may not be necessary. The answer, anyway, is, with great
difficulty and at great cost, as I said.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
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